代码实现时间片轮转调度、优先数调度、最短进程优先、最短剩余时间优先四种调度方法

时间片轮转调度：

class Process:
    def __init__(self, name, arrival_time, burst_time):
        self.name = name
        self.arrival_time = arrival_time
        self.burst_time = burst_time
        self.remaining_time = burst_time

    def execute(self, quantum):
        if self.remaining_time > quantum:
            self.remaining_time -= quantum
            return quantum
        else:
            time_executed = self.remaining_time
            self.remaining_time = 0
            return time_executed


def schedule_rr(processes, quantum):
    time = 0
    num_processes = len(processes)
    queue = processes[:]
    completed_processes = []
    current_process = None

    while len(completed_processes) < num_processes:
        # add arriving processes to the queue
        for p in processes:
            if p.arrival_time == time and p not in queue and p not in completed_processes:
                queue.append(p)

        # get next process to execute
        if not current_process or current_process.remaining_time == 0:
            if queue:
                current_process = queue.pop(0)
            else:
                time += 1
                continue

        # execute current process for a quantum
        time_executed = current_process.execute(quantum)
        time += time_executed

        # check if process has completed
        if current_process.remaining_time == 0:
            completed_processes.append(current_process)

    return completed_processes

优先数调度：

class Process:
    def __init__(self, name, arrival_time, burst_time, priority):
        self.name = name
        self.arrival_time = arrival_time
        self.burst_time = burst_time
        self.remaining_time = burst_time
        self.priority = priority

    def execute(self):
        self.remaining_time -= 1


def schedule_priority(processes):
    time = 0
    num_processes = len(processes)
    queue = processes[:]
    completed_processes = []
    current_process = None

    while len(completed_processes) < num_processes:
        # add arriving processes to the queue
        for p in processes:
            if p.arrival_time == time and p not in queue and p not in completed_processes:
                queue.append(p)

        # get next process to execute
        if not current_process or current_process.remaining_time == 0:
            if queue:
                queue.sort(key=lambda p: p.priority)
                current_process = queue.pop(0)
            else:
                time += 1
                continue

        # execute current process
        current_process.execute()
        time += 1

        # check if process has completed
        if current_process.remaining_time == 0:
            completed_processes.append(current_process)

    return completed_processes

最短进程优先：

class Process:
    def __init__(self, name, arrival_time, burst_time):
        self.name = name
        self.arrival_time = arrival_time
        self.burst_time = burst_time
        self.remaining_time = burst_time

    def execute(self):
        self.remaining_time -= 1


def schedule_sjf(processes):
    time = 0
    num_processes = len(processes)
    queue = processes[:]
    completed_processes = []
    current_process = None

    while len(completed_processes) < num_processes:
        # add arriving processes to the queue
        for p in processes:
            if p.arrival_time == time and p not in queue and p not in completed_processes:
                queue.append(p)

        # get next process to execute
        if not current_process or current_process.remaining_time == 0:
            if queue:
                queue.sort(key=lambda p: p.burst_time)
                current_process = queue.pop(0)
            else:
                time += 1
                continue

        # execute current process
        current_process.execute()
        time += 1

        # check if process has completed
        if current_process.remaining_time == 0:
            completed_processes.append(current_process)

    return completed_processes

最短剩余时间优先：

class Process:
    def __init__(self, name, arrival_time, burst_time):
        self.name = name
        self.arrival_time = arrival_time
        self.burst_time = burst_time
        self.remaining_time = burst_time

    def execute(self):
        self.remaining_time -= 1


def schedule_srt(processes):
    time = 0
    num_processes = len(processes)
    queue = processes[:]
    completed_processes = []
    current_process = None

    while len(completed_processes) < num_processes:
        # add arriving processes to the queue
        for p in processes:
            if p.arrival_time == time and p not in queue and p not in completed_processes:
                queue.append(p)

        # get next process to execute
        if not current_process or current_process.remaining_time == 0:
            if queue:
                queue.sort(key=lambda p: p.remaining_time)
                current_process = queue.pop(0)
            else:
                time += 1
                continue

        # execute current process
        current_process.execute()
        time += 1

        # check if process has completed
        if current_process.remaining_time == 0:
            completed_processes.append(current_process)

    return completed_processes